Conventionally, in order to improve wet grip performance on straight traveling as well as dry grip performance on cornering, various motorcycle tires have been proposed. For instance, a motorcycle tire including a tread portion with a central region and a shoulder region disposed on both sides of the central region has been proposed, wherein the respective central and shoulder regions have a different groove area ratio. The tire includes the central region with a high groove area ratio and the shoulder regions with a low groove area ratio.
Meanwhile, motorcycle tires are required to have excellent cornering performance. In order to improve cornering performance, it is necessary to improve the transient characteristic during cornering. The transient characteristic is represented by the degree of change in steering angle of a motorcycle during cornering. For example, in case of a tire with an excellent cornering performance, the change in steering angle during cornering of period from the beginning to the end is small. Thus, a rider may steer the motorcycle smoothly. On the other hand, in case of a tire with poor cornering performance, the change in steering angle during cornering of period from the beginning to the end is large. Thus, a rider may be difficult to steer the motorcycle smoothly. The change in steering angle of a motorcycle during cornering basically depends on change in a pattern rigidity of the tread portion of the tire. That is, when the change in the pattern rigidity in an axial direction of the tire is large, the change in steering angle tends to be large.
In case of a tire with different groove area in the respective central region and the shoulder region of the tread portion, the change in the pattern rigidity tends to be large. Accordingly, the above mentioned tire may be difficult to obtain an excellent transient characteristic owing to large change in the steering angle during cornering.